Cadbury is opening its own newsagents where chocoholics can get their hands on one of 10,000 free bars of Dairy Milk.

But there's a catch: you'll have to exchange a bit of old tat to get your hands on one of the bars.

The world-renowned chocolate maker will open the unusual shop for three days in different cities across the UK, starting in Soho in London next week.

The promise of free chocolate is bound to get hundreds if not thousands of chocoholics rushing to Cadbury's pop-up

From 10am until 6pm, customers can walk into the newsagents to swap an old knick-knack or unwanted items for a bar of free chocolate, one of 10,000 in each shop.

Cadbury, owned by American multinational Mondelez, is launching the pop-up in tribute to its latest advert in which a kindly newsagent allows a young girl to buy her mother a Dairy Milk bar in exchange for the contents of her pockets: a few buttons, a plastic ring, and a fake coin.